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Diet Formulation and Evaluation

Feeding diets with lowered protein content reduces nitrogen input, improves nitrogen utilization efficiency, and reduces nitrogen losses from manure. Reducing dietary protein also benefits the producer by reducing feed cost and improving overall farm profitability. These interventions, however, have to be balanced with the risk of loss in milk production. If the true animal requirements for metabolizable protein are not met, long-term production cannot be sustained.

Herds with lactating dairy cattle exceeding fecal phosphorus levels from 0.55 to 0.80% on a dry matter basis have opportunity for improvement. Herds that have implemented precision feeding and removed all inorganic phosphorus can maintain these levels. Some contracted farms are observing fecal phosphorus levels over 1.0% on a dry matter basis. Based on the herds in this project, fecal phosphorus below 0.80% is achievable.

Feed efficiency is a simple measure to determine the relative ability of cows to turn feed nutrients into milk or milk components. In the simplest terms it is the pounds of milk produced per pound of dry matter consumed. This measure should always be a consideration of dairy diets and becomes increasingly important during times of tight profit margins.

Agriculture contributes approximately 6 to 7% of the total U.S. greenhouse gas emissions. Methane from enteric (microbial) fermentation represents 20% and manure management 7% of the total methane emitted. Some dietary practices that have been shown to reduce methane include addition of ionophores, fats, use of high quality forages, and increased use of grains.

This factsheet will describe the variation found in production of milk components, factors that contribute to this variation, and strategies to improve component production.

Microsoft Excel, 103.1 kB

This spreadsheet calculates gross milk price using multiple-component pricing with the option of a somatic cell count adjustment (the formula used in the Mideast Federal Order). To calculate a milk price for the Northeast Federal Order, the somatic cell count adjustment can be set to zero. Users can calculate their current price, project milk price at various levels of fat and protein, evaluate income over feed cost, and calculate total components shipped, providing a complete picture of the impact milk components and milk yield have on the farm's gross income. The spreadsheet also includes a page that can be used to track mailbox milk price over time.

This article explains how nitrogen fed to cows contributes to ammonia emissions and explores feeding strategies to reduce excess nitrogen in the diet.

Environmental concerns with phosphorus (P) have forced the animal industry to re-evaluate the levels formulated in diets. It has been demonstrated in numerous research trials that excess P intake equates to excess P out in the manure.

This publication addresses the phosphorus needs of the dairy cow and ways in which dietary phosphorus can be reduced.

Total mixed rations (TMR) help dairy cows achieve maximum performance and are the most adopted method for feeding high producing, indoor-housed dairy cows in the world. Advantages and disadvantages of TMR feeding systems are presented as well as strategies for successfully managing TMR programs.

This fact sheet will examine the limitations of laboratory analysis methods for predicting forage quality, what the different components are that make up the carbohydrate portion of feeds, and the effect farm management practices have on carbohydrate nutrition.

PDF, 1.7 MB

Much information is needed to evaluate dairy herd nutrition and feeding programs. Collecting this information in a systematic manner helps to ensure that important items are not overlooked. This publication contains worksheets to help capture information necessary for a thorough feeding program evaluation, including body condition scores, feeding systems, available feeds, management records, and lactation curves.